Cohort profile of the GOALS study: A large-scale research of physical activity in Dutch students. - Renate H. M. de Groot; Martin L. van Dijk; Paul A. Kirschner (Br. J. Educ. Technol., 2015)

Learning and navigating in hypertext: Navigational support by hierarchical menu or tag cloud? - Jaap Walhout; Saskia Brand-Gruwel; Halszka Jarodzka; Martin van Dijk; Renate de Groot; Paul A. Kirschner (Comput. Hum. Behav., 2015)